Depends on the style of wing chun you study. Many wing chun systems prefer to fight on the outside gate and will accordingly use a single transition to the outside.
The VT system I train also prefers outside, but we must know how to fight on the inside.
Often, the opportunity to take the outside line with a direct attack will present itself.
Unless a mistake like crossing oneself has been made (e.g. right inside right) requiring immediate switch, there is no reason to jump from defensive action on the inside to another defensive action on the outside, like
biu biu against the same arm, and even when switching it will preferably be with an attacking action.
If you stay in the middle and the opponent is raining punches on you, you'll probably wind up trading blows anyways. Thus many systems see the value of finding a method to escape to the outside (a safer position).
It's just that in your example, right
biu to the inside of the opponent's left punch, from my perspective you are not in a particularly poor position that needs escaping from. In may be the very next punch that takes you to the outside line.
Worrying about this gate or that gate and how to escape unnecessarily from here to there with this hand or that hand technique in the heat of a fight is highly problematic.
The problem being thinking and the time gap between registering options, decision and action.
For this reason, in my approach, we work direct from where we are and try not to make gate jumps except via attack.
That means an intuitive method that cuts back on things that require thinking and decision making when there is little to no time for that.